Eastern Equine Encephalitis in Latin America
Eastern Equine Encephalitis in Latin America
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DOI：
10.1056/nejmoa1212628
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发表时间：
2013-08-22
影响因子：
158.5
通讯作者：
Weaver, Scott C.
中科院分区：
文献类型：
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作者：
Carrera, Jean-Paul;Forrester, Naomi;Weaver, Scott C.
背景东部马脑炎（EEE）和委内瑞拉马脑炎（VEE）病毒是感染美洲人类和马的病原体。2010年5月至8月初在巴拿马报告了人类和马的神经系统疾病暴发。方法采用抗体测定和病毒RNA检测，分离住院患者血清中的病毒。通过加强监测发现了更多病例。结果19例患者因脑炎住院。其中EEE确诊7例，VEE确诊3例，两种病毒同时感染1例；死亡3例，其中1例确诊VEE。EEE患者的临床表现包括脑损伤、癫痫发作演变为癫痫持续状态和神经系统后遗症。在主动监测期间，又发现了99例甲型病毒感染疑似或可能病例。确诊EEE 13例，VEE 11例，双重感染1例。马共确诊EEE 50例，VEE 8例；混合病因与11例马相关。对2例马感染EEE病毒和1例人感染VEE病毒的分离株进行系统发育分析表明，这些病毒属于以前在巴拿马发现的地方性动物谱系，而不是新引入的病毒。结论拉丁美洲的人类EEE病例可能是由于生态变化导致人类与地方性动物传播周期的接触增加，EEE病毒株的遗传变化导致人类毒力增加，或者宿主范围改变的结果。
BACKGROUNDThe eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) viruses are pathogens that infect humans and horses in the Americas. Outbreaks of neurologic disease in humans and horses were reported in Panama from May through early August 2010.METHODSWe performed antibody assays and tests to detect viral RNA and isolate the viruses in serum samples from hospitalized patients. Additional cases were identified with enhanced surveillance.RESULTSA total of 19 patients were hospitalized for encephalitis. Among them, 7 had confirmed EEE, 3 had VEE, and 1 was infected with both viruses; 3 patients died, 1 of whom had confirmed VEE. The clinical findings for patients with EEE included brain lesions, seizures that evolved to status epilepticus, and neurologic sequelae. An additional 99 suspected or probable cases of alphavirus infection were detected during active surveillance. In total, 13 cases were confirmed as EEE, along with 11 cases of VEE and 1 case of dual infection. A total of 50 cases in horses were confirmed as EEE and 8 as VEE; mixed etiologic factors were associated with 11 cases in horses. Phylogenetic analyses of isolates from 2 cases of equine infection with the EEE virus and 1 case of human infection with the VEE virus indicated that the viruses were of enzootic lineages previously identified in Panama rather than new introductions.CONCLUSIONSCases of EEE in humans in Latin America may be the result of ecologic changes that increased human contact with enzootic transmission cycles, genetic changes in EEE viral strains that resulted in increased human virulence, or an altered host range.